REDUCING AIRPORT DELAYS USING INFORMATION AND ANALYTICS

Abstract

A system and method for receiving, from a data source, at least one type of information for a plurality of aircraft, calculating efficiency data based on the received information, distributing the efficiency data to users of the system and storing the calculated efficiency data, the efficiency data including an average separation between arriving aircraft, an arrival rate an airport, an elapsed time from a point of interest to an arrival of the aircraft at an airport, a comparison of an actual base leg initiation to an optimal base leg initiation for an aircraft and a comparison of an estimated time for passing fixed points on an arrival path and the actual time for passing the fixed points.

Description

PRIORITY CLAIM/INCORPORATION BY REFERENCE

This application claims the benefit of U.S. patent application Ser. No. 11/672,821 filed on Feb. 8, 2007 and entitled “Reducing Airport Delays Using Passive Radar Information And Analytics” which claims priority to U.S. Provisional Patent Application 60/771,730 filed on Feb. 9, 2006 and entitled “Reducing Airport Delays Using Passive Radar Information And Analytics,” both of which are expressly incorporated herein, in their entirety, by reference.

BACKGROUND INFORMATION

The ability of airlines to operate profitably depends, in large part, on efficient utilization of resources such as aircraft, personnel, and access to runways and other airport facilities. The smoothness and speed of the flow of air traffic in and around an airport, particularly relating to the ability to predict and reduce delays, is a significant factor contributing to such efficiency. By maintaining traffic flow at or near optimal conditions, fuel consumption may be minimized; aircraft flight time may be reduced; and delays may be avoided, resulting in improved customer relations and enhanced prospects for repeat business.

Airlines are generally able to monitor their own internal operations to ensure efficiency. However, they do not typically have the ability to monitor airport operations on a broader scale in order to analyze and act on delays. Therefore, if airlines were able to access improved information, they could better communicate with air traffic control (“ATC”) in order to improve airport throughput, reduce delays, and improve the efficiency of their operations.

SUMMARY OF THE INVENTION

A system and method for receiving, from a data source, at least one type of information for a plurality of aircraft, calculating efficiency data based on the received information, distributing the efficiency data to users of the system and storing the calculated efficiency data, the efficiency data including an average separation between arriving aircraft, an arrival rate an airport, an elapsed time from a point of interest to an arrival of the aircraft at an airport, a comparison of an actual base leg initiation to an optimal base leg initiation for an aircraft and a comparison of an estimated time for passing fixed points on an arrival path and the actual time for passing the fixed points.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an exemplary system for determining airport efficiency data according to an exemplary embodiment.

FIG. 2 shows a simplified exemplary view of a typical route an aircraft takes to approach an airport.

FIG. 3 shows an exemplary method for determining airport efficiency data according to an exemplary embodiment.

FIG. 4 shows a second exemplary method for determining airport efficiency data according to an exemplary embodiment.

DETAILED DESCRIPTION

The exemplary embodiments provide an airport efficiency monitoring system for delivery of information via a communication network which may be, for example, the Internet, a corporate intranet, etc. The information that is provided to the users (e.g., via a graphical user interface such as a World Wide Web browser) may include various metrics of airport efficiency to be discussed below, as well as measured aircraft performance data used to calculate these results. The exemplary embodiments are described as a web based system; however, those skilled in the art will understand that there may be any number of other manners of implementing the present invention in embodiments that are not web based. The exemplary embodiments may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals.

FIG. 1 illustrates an exemplary system 1. A data capture arrangement 10 obtains data relating to the operation of a plurality of aircraft 20, 22. In this exemplary embodiment, the data capture arrangement 10 may include one or more Passive Secondary Surveillance Radar (“PSSR”) systems. A PSSR system may be, for example, the PASSUR® system sold by Megadata Corporation of Bohemia, N.Y. Those skilled in the art will understand that the using a PSSR system as the data capture arrangement is only exemplary and that any other type of data capture arrangement may also be used. In addition, the data capture arrangement 10 is not limited to a system that actually captures data, but may be instead, an input of data from another system that collects data. For example, the system 1 does not need to actively capture data using a PSSR system, but system 1 may merely receive data as a data feed from another system that directly or indirectly captures data. For example, the data input may be a data feed from the Federal Aviation Administration (“FAA”) or any other third party that collects data on aircraft. One example of a data feed is an ADS-B (Automatic Dependent Surveillance Broadcast) data feed. An ADS-B system uses Global Navigation Satellite System (GNSS) technology and a relatively simple broadcast communications link as its fundamental components. ADS-B accuracy does not seriously degrade with range, atmospheric conditions, or target altitude and update intervals do not depend on the rotational speed or reliability of mechanical antennas. Again, even ADS-B is only exemplary and any data feed, whether radar based or non-radar based may be used as the input feed to act as the data capture arrangement 10 in system 1. In addition, the data capture arrangement may be a one or more, or a combination thereof, of data input feeds and data capture systems. Therefore, as used throughout this description, the term “data capture arrangement” does not require the actual capturing of data, but may also include the receiving of data from other sources. This is illustrated in FIG. 1 as the data capture arrangement 10 including one or both of a radar capture system as illustrated by the radar dish or a data input feed.

Data collected and/or input as a data feed by the data capture arrangement 10 may include, but is not limited to, aircraft position, VFR/IFR conditions, type of arriving and/or departing aircraft, separation distance between arriving and departing aircraft, arrival rate of arriving and/or departing aircraft, time from an outer boundary to landing, aircraft speed at a plurality of points during arrival and/or departure, actual airport runway configuration, location of base leg turns, and location of “stream blending” for arriving aircraft.

With the exception of many small airports that serve general aviation, larger airports generally have a Secondary Surveillance Radar (“SSR”) system. SSR includes a rotating radar that sends interrogation signals at a frequency of 1030 MHz to aircraft in the vicinity of the airport. Transponders aboard aircraft respond to the interrogations by transmitting a response signal back to the radar at a frequency of 1090 MHz. In addition to the SSR, PSSR may be sited near, but not on, the airport grounds. PSSR may include two antenna systems: a fixed, directional high gain 1030 MHz antenna aimed toward the SSR for receiving the interrogation signals; and a stationary array of directive antennas arranged in a circle to detect the 1090 MHz responses from the aircraft transponders. PSSR's may be placed at known distances and directions from a corresponding SSR.

Using the time relationships between received signals, i.e., the interrogations and responses, the known distances from the SSR, and the known direction from each PSSR to the SSR, the PSSR determines the location of aircraft relative to a reference location, e.g., the airport. Response signals from the aircraft received by PSSR include Mode A transponder beacon signals, Mode C transponder beacon signals and Mode S transponder beacon signals. The Mode A signal comprises a four (4) digit code which is the beacon code identification for the aircraft. The Mode C signal additionally includes altitude data for the aircraft. The Mode S signal is either a 56 bit surveillance format having a 32 bit data/command field and a 24 bit address/parity field or a 112-bit format allow for the transmission of additional data in a larger data/command field. PSSR receives the beacon code and altitude data from the received signals and calculates aircraft position (e.g., range, azimuth) and ground speed based on the timing of the receipt of the signals and the known radar locations. Thus, position information or target data points for each of the aircraft is derived based on the physical characteristics of the incoming signals, rather than based on position data contained in the signal itself.

As described in detail above, the data capture arrangement 10 is not limited to a PSSR system, but may be a data feed such as an ADS-B data feed. The exemplary system 1 may use this data feed information in the same manner as the PSSR system data. For example, the ADS-B data feed may include some or all of the data that is captured by a PSSR system. In addition, the ADS-B data feed may also include additional information that is more than a PSSR system may collect. As described above, not all airports will have PSSR systems. However, as GPS becomes more ubiquitous, it is possible that all aircraft will be equipped with a system to collect GPS data on location and relay this information to ground terminals which may then pass this information, and any information derived from the GPS location information (e.g., speed, direction, etc) in a data feed, thereby allowing ground control to have information about all aircraft in the sky.

The data capture arrangement 10 conveys some or all of the recorded data to a processing unit 30. The processing unit 30 may be, for example, a standard PC based server system running an operating system such as LINUX. Those skilled in the art will understand that any computing platform may be used for the processing unit 30. The processing unit 30 analyzes the raw data from the data capture arrangement to determine one or more results requested by users 60-62.

In one exemplary embodiment, the data collected by the data capture arrangement 10 is used to calculate efficiency data of an average separation between arriving aircraft by observing the physical distance between aircraft in the approach path. That is, the data capture arrangement 10 collects data that gives the position (e.g., x,y,z coordinates) of each plane that is being monitored. This data may be used to calculate the physical distance at any point time between aircraft being monitored. Such distances may be averaged over discrete periods of time (e.g., hours, days, etc.) and may then be compared to the average separation from previous days, months, etc. In one exemplary embodiment, the comparing to previous periods is performed for periods having similar conditions (e.g., weather conditions, days of the week, holiday/non-holiday, etc.). If the average separation during a given period of time is greater than the average separation during a similar period of time in the past (or, alternately, if the average separation is greater than the separation required for safe flight under current weather conditions), then the airport is not maximizing its throughput. An airline with detailed knowledge of this type will be better informed when negotiating with ATC for landing/takeoff slots, and will thus be able to help improve efficiency. This type of information that may be derived from the data collected by the data capture arrangement 10 allows the airline to effectively collaborate with the ATC, the airport and the FAA because the airline has the information providing insight into the current conditions of airport efficiency and how this compare to pas performance.

Another type of efficiency data that may be determined from the data provided by the data capture arrangement 10 is an aircraft arrival rate. This is obtained by measuring the number of aircraft that arrive over a given period of time. The present arrival rate may then be compared with either previous measured arrival rates (as above, ideally from periods with similar conditions), or with the projected arrival rate based on arrival schedules. If the present arrival rate is lower than projected, an airline is better able to anticipate delays, and may also be able to contact ATC to obtain an explanation for the lower arrival rate and/or request an increase.

For example, if the airline understands that the present arrival rate is less than the projected arrival rate based on the schedule, the airline may be able to determine delays and inform passengers. The airline may also provide for anticipatory delays, e.g., because of a slow arrival rate, the airline may determine that flights that are scheduled several hours out may experience delays, and therefore be able to keep passengers better informed. It should be noted that the exemplary embodiments may be able to determine the delays. For example, based on the actual arrival rate, the exemplary embodiments may adjust the arrival/departure schedule times.

In another example, the airline may be able to determine, based on the current arrival rate and historical arrival rates, exactly how the schedule will be affected. That is, the exemplary embodiments may compare a historical time period having a similar arrival rate for which all the data is known (e.g., arrival times, delays, etc.) to the current arrival rate to approximate what will happen in the present/future. However, not only can the airline anticipate any issues in order to inform passengers, but the airline can also use this information to interact with the ATC, airport, FAA, etc. in order to take corrective action to mitigate any adverse effects of the particular identified inefficiency.

In another example, another type of efficiency data that may be determined is an elapsed time from an outer boundary to landing. Once again, the data collected by the data capture arrangement 10 may indicate when each aircraft passes an outer boundary and when the aircraft lands, thereby allowing a calculation of the elapsed time for the traversal from the outer boundary to the runway in use. To provide accurate efficiency data, the elapsed time efficiency data may be sorted by, for example, aircraft type, runway, weather conditions, etc. Once again, this current data may then be compared to historical averages under similar conditions, thereby indicating if there is any current inefficiency that may be corrected.

Aircraft speed at various points during arrival/departure is another type of efficiency data that may be determined. Points of interest may include an outer boundary, a fixed point in the takeoff/landing flight path, and a threshold point just before landing, etc. Similar to the previous types of efficiency data, if aircraft are passing these points at speeds that are too slow (given the type of aircraft and the weather conditions), the airport is running inefficiently and throughput is not being maximized. This data may be passed on to the ATC so that the ATC may indicate to pilots that they may increase their airspeed at the various points in order to increase efficiency by allowing additional planes to takeoff/land.

Another example of efficiency data that may be determined is information regarding actual airport runway configuration. As described above, the data collected by the data capture arrangement 10 may include the physical location of the aircraft. This physical location may be correlated with the location of runways to determine the runway on which an aircraft takes off or lands. This may then be compared to the planned runway configuration in view of weather, time of day, etc. Such a comparison may show, for example, that ATC is underutilizing one runway in favor of another. When an airline becomes aware of configuration changes, it can contact ATC to obtain an explanation and/or request a change back to an optimal runway configuration.

Another example of efficiency data that may be determined is the location of base leg turns. FIG. 2 shows a typical flight path followed by a landing aircraft 210 when approaching airport 220 for landing, with the prevailing wind blowing in the direction indicated by arrow 230. Landing aircraft 210 travels with the wind along downwind leg 240, turns into crosswind base leg 250, and then turns into the wind for final approach 260. Base leg 250 must be located sufficiently downwind from airport 220 in order for the pilot of landing aircraft 210 to make a safe and controlled approach. The proper position for base leg 250 is dependent on, among other factors, the model of airplane 100 and the weather conditions at the time of landing. If the pilot of landing aircraft 210 turns into base leg 250 too far downwind, however, the approach takes more time, resulting in increased fuel consumption and diminished airport throughput. Therefore, by monitoring the location of base leg turns, an airline can optimize its own fuel consumption, and can inform the ATC if other airlines are operating in a manner that may result in diminished throughput.

Another type of efficiency data that may be determined is a variance between actual time of arrival and estimated time of arrival from one or more fixed points along an arrival path. By observing such speed variances, airlines may become aware of possible “surges” and may communicate with ATC to request that arrival speeds be smoothed. This can result in increased fuel efficiency.

Another example of efficiency data that may be determined is the location where stream blending is taking place among arriving aircraft. When approaching an airport for landing, multiple aircraft will follow the same approach path (e.g., the path shown in FIG. 2), separated by at least a minimum safe distance. One reason for this is to minimize the effect that one aircraft's jet stream will have on other aircraft. Aircraft following similar paths will create similar jet streams; the process of merging approaching aircraft into such a similar path is known as “stream blending.” Having predictable, blended streams created by approaching aircraft is desirable because it results in calmer, more predictable air conditions for both arriving and departing aircraft. However, at times stream blending occurs further from the airport than is necessary. This can cause aircraft to fly a longer approach path in order to merge their streams further away from the airport. The result of these suboptimal trajectories is more time spent on approach, increased fuel usage, and delayed arrivals. Therefore, information about the location of stream blending may be useful for airlines to request that the ATC route traffic more efficiently.

It should be noted that the above examples of efficiency data are only exemplary and that other types of efficiency data may be determined using the data received from the data capture arrangement 10. Thus, efficiency data may be any data that may be calculated from the data or other data in combination with the data from the data capture arrangement 10 (e.g., active radar data, FAA data, fixed data such as schedules, runway locations, etc.) to determine how efficiently an airport, aircraft and/or airline is operating. This includes a combination of one or more of the efficiency metrics discussed above being used to create a composite metric for overall airport efficiency. Such a metric may be based on average aircraft separation and arrival rates, and could additionally consider aircraft type and weather conditions. By analyzing such a metric, an airline can learn whether the ATC has overperformed or underperformed, what an airport's true capacity is, how to schedule its flights optimally, and how to best collaborate with ATC and airport administration to improve efficiency.

It should also be noted that, while the preceding paragraphs describe efficiency data that may be calculated from measured information about arriving flights, many of the same metrics are equally applicable to departing flights. The results of such measurements may be used in substantially the same manner as data for arriving flights.

Once calculations are complete, the resulting data is delivered to the users 60-62 of the system 1. The data processing unit 30 may also include web server 40 software to distribute data to the users 60-62 of the system 1. In the exemplary embodiment of the system 1 shown in FIG. 1, the data generated by the data processing unit 30 may be transmitted to a plurality of users (e.g., users 60-62) via a communications network 50 (e.g., the Internet). The web server 40 software may host a web page containing the necessary data and information to display the tracking information by local users. The users 60-62 may operate a web browser such as Microsoft's Internet Explorer, Mozilla Firefox, or other third-party web browsing software which may access the web page hosted by web server 40 software. The web browser software operated by the users 60-62 will manage the data that is transmitted to the client users 60-62 from the web server 40 software of the data processing unit 30. The data transferred from the data processing unit 30 may be, for example, HTML code or applets.

Thus, when a user (e.g., users 60-62) connects to the data processing unit 30 via communications network 50, the web server 40 software may send an applet to the user to enable the user to display and control the data sent from the data processing unit 30 to the user. The applet code transferred to the user may be executed by the user's browser to display the tracking information. As the user remains connected to the data processing unit 30, the web server 40 software will continue to update the data on the user's screen. The update may be performed automatically each time the data processing unit 30 receives updated information from the data capture arrangement 10. Updates from PSSR sources may occur approximately every 4.6 seconds, i.e., the time that the data processing unit 30 receives updates from a PSSR source plus the processing and data transmission times. Updates from other sources such as an ADS-B data feed may occur at faster and/or slower rates. The data may be formatted by the data processing unit 30 and delivered to the web browser of the users 60-62 in any standard web browser readable format, for example, HTML format, Java, Java Script, etc.

Data sent from the data processing unit 30 to the users 60-62 via communications network 50 may be displayed in a variety of ways. For example, results may be displayed as absolute numbers (e.g., the actual airport arrival rate, displayed as bar graphs over time, with each bar representing a selected time interval). Alternately, actual results may be shown in comparison to projected results (e.g., actual arrival rate vs. projected arrival rate; such a display would put the actual number into an appropriate context for the user, who would then be better able to act on the information). As another option, information could be displayed in the form of live averages or historical averages (e.g., the average aircraft separation rate, both current and over a selected historical period; this would enable the user to be better informed when discussing an ongoing disruption with ATC). An additional display view would be to show data in the form of a bell curve (e.g., time from an outer marker to landing; such a display could be in the form of a numerical standard deviation from the mean, or a visual representation of a bell curve, making outliers easily identifiable). Finally, the results could be displayed in the form of an algorithm as a combination of many of the different variables. That is, the information could be delivered simply as an efficiency metric on, for example, a scale of 0-100 for any particular efficiency metric or a combination of efficiency metrics.

FIG. 3 illustrates an exemplary method 300 by which data is received, processed, and routed to the user. In step 310, the airport SSR sends interrogation signals to aircraft in the vicinity of the airport. In step 320, the interrogation signals are received by aircraft and by the PSSR. In step 330, aircraft reply to the interrogation signals. In step 340, the replies are received by the airport SSR and by the PSSR. In step 350, the interrogation signals and their replies are sent by the PSSR to the data processing unit. In step 360, the data processing unit receives a request for data from a user. In step 370, the data processing unit performs the calculations required to generate the requested data from the raw information received from the PSSR. In step 380, the data processing unit transmits the requested data to the user via a communications network. In step 390, the data is displayed to the user through a graphical user interface, such as those of the types described above.

FIG. 4 illustrates a second exemplary method 400 by which data is received, processed, and routed to the user. In contrast to method 300, in method 400 it is considered that the data capture arrangement 10 receives information as a data input feed, rather than actually capturing the information via a PSSR system. In step 410, data from the data capture arrangement 10 is forwarded to the data processing unit 30. As described above, the data capture arrangement 10 may receive information as a data feed (e.g., the ADS-B data feed). The data capture arrangement 10 may forward this data as it is received and/or the data capture arrangement 10 may derive additional information from the received data prior to forwarding the data and the derived data to the data processing unit 30. In step 420, the data processing unit 30 receives a request for data from a user. In step 430, the data processing unit 30 performs the calculations required to generate the requested data from the raw information received from the data capture arrangement 10. In step 440, the data processing unit 30 transmits the requested data to the user via a communications network. In step 4500, the data is displayed to the user through a graphical user interface, such as those of the types described above.

In the preceding specification, the exemplary embodiments have been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broadest spirit and scope of the present invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense.

Claims

1. A system, comprising:

a data receiving arrangement receiving, from a data source, at least one type of information for a plurality of aircraft;

a data processing arrangement calculating efficiency data based on the received information;

a data distribution arrangement organizing efficiency data into a displayable file and distribute the file to users of the system; and

a storage arrangement storing the calculated efficiency data, the stored efficiency data being historical efficiency data

2. The system of claim 1, wherein the data source is an ADS-B data feed.

3. The system of claim 1, wherein the at least one type of information is location data for each of the plurality of aircraft as the aircraft are arriving at an airport facility, the efficiency data being an average separation between the plurality of aircraft as the aircraft arrive at the airport facility, the data processing arrangement further configured to compare the average separation for a current time period to one of an average separation for a previous time period stored by the storage arrangement and a predetermined average separation based on safety considerations, the data distribution arrangement further configured to distribute to the users an indication of the comparison.

4. The system of claim 3, wherein the storage arrangement is configured to store the historical efficiency data based on characteristics and the data processing arrangement compares the average separation for the current time period to only those average separation for the previous time periods that have similar characteristics as the current time period.

5. The system of claim 1, wherein the at least one type of information indicates, for each of the plurality of aircraft, a time that each aircraft arrives at an airport facility, the efficiency data being an arrival rate of the aircraft at the airport facility, the data processing arrangement further configured to compare the arrival rate for a current time period to an arrival rate for a previous time period stored by the storage arrangement, the data distribution arrangement further configured to distribute to the users an indication of the comparison.

6. The system of claim 5, wherein the data processing arrangement is further configured to determine a previous time period stored in the storage arrangement that has an arrival rate that is similar to the arrival rate for a current time period, the storage arrangement storing further information for the previous time period, the data distribution arrangement further configured to distribute the further information for the previous time period to users, wherein the further information includes schedule delays for the previous time period.

7. The system of claim 1, wherein the at least one type of information indicates, for each of the plurality of aircraft, a time that each aircraft passes a predetermined point of interest and a time each aircraft arrives at an airport facility, the efficiency data being an elapsed time from the point of interest to arrival for each aircraft, wherein the point of interest is one of an outer boundary, a fixed point in a landing flight path and a threshold point before landing.

8. The system of claim 1, wherein the at least one type of information is location data for each of the plurality of aircraft as the aircraft are arriving at an airport facility, the location data indicating a position where each aircraft initiates a base leg, the efficiency data being a comparison of the position of the base leg initiation for each aircraft and an optimal position of a base leg for each aircraft.

9. The system of claim 1, wherein the at least one type of information indicates, for each of the plurality of aircraft, a time that each aircraft passes multiple fixed points along an arrival path, the efficiency data being a variance between the time that each aircraft passes the multiple fixed points along the arrival path and an estimated time for each aircraft to pass the multiple fixed points along the arrival path.

10. The system of claim 1, wherein the data receiving arrangement further receives a second type of information from a second data source, the efficiency data being calculated based on the received information and the second type of information, wherein the second type of information includes one of an airline schedule, a location of a runway, an expected runway configuration, an expected fuel usage, a type of aircraft and weather conditions.

11. A method, comprising:

receiving, from a data source, at least one type of information for a plurality of aircraft;

calculating efficiency data based on the received information; and

distributing the efficiency data to users;

storing the calculated efficiency data

12. The method of claim 11, wherein the at least one type of information is location data for each of the plurality of aircraft as the aircraft are arriving at an airport facility, the efficiency data being an average separation between the plurality of aircraft as the aircraft arrive at the airport facility.

13. The method of claim 12, further comprising:

comparing the average separation for a current time period to one of an average separation for a previous time period and a predetermined average separation based on safety considerations; and

distributing to the users an indication of the comparison.

14. The method of claim 13, wherein the comparing to a previous time period is limited to time periods having similar characteristics as the current time period.

15. The method of claim 11, wherein the at least one type of information indicates, for each of the plurality of aircraft, a time that each aircraft arrives at an airport facility, the efficiency data being an arrival rate of the aircraft at the airport facility.

16. The method of claim 15, further comprising:

comparing the arrival rate for a current time period to an arrival rate for a previous time period; and

distributing to the users an indication of the comparison.

17. The method of claim 15, further comprising:

determining a previous time period that has an arrival rate that is similar to the arrival rate for a current time period; and

distributing information for the previous time period to users, wherein the information includes schedule delays for the previous time period.

18. The method of claim 11, wherein the at least one type of information indicates, for each of the plurality of aircraft, a time that each aircraft passes a predetermined point of interest and a time each aircraft arrives at an airport facility, the efficiency data being an elapsed time from the point of interest to arrival for each aircraft, wherein the point of interest is one of an outer boundary, a fixed point in a landing flight path and a threshold point before landing.

19. The method of claim 11, wherein the at least one type of information is location data for each of the plurality of aircraft as the aircraft are arriving at an airport facility, the location data indicating a position where each aircraft initiates a base leg, the efficiency data being a comparison of the position of the base leg initiation for each aircraft and an optimal position of a base leg for each aircraft.

20. The method of claim 11, wherein the at least one type of information indicates, for each of the plurality of aircraft, a time that each aircraft passes multiple fixed points along an arrival path, the efficiency data being a variance between the time that each aircraft passes the multiple fixed points along the arrival path and an estimated time for each aircraft to pass the multiple fixed points along the arrival path.